<_x0034_01004170>

401004170 19 2016-03-15T10:12:16.827-06:00 69175 PDC ENERGY INC

1775 SHERMAN STREET - STE 3000

DENVER CO 80203 Zack Liesenfeld 970 506-9273 970 373-6581 Zack Liesenfeld EHS Representative 2016-03-15T10:12:16.827-06:00 2016-03-15T10:12:16.797-06:00 444936 in process Cwasko 2016-03-11T13:57:26.563-07:00 Cwasko zack.liesenfeld@pdce.com 0.00000 zack.liesenfeld@pdce.com Zliesenfeld Zliesenfeld 2016-03-15T10:12:10.797-06:00 400992777 401004170 ALLISON, RICK 2016-02-18T00:00:00-07:00 TANK BATTERY WELD NESE 12 6N 65W 6 Y CROP LAND Sunny and cool 0 0 A historical release was discovered on the Williamson 43-12 site while abandoning the production facility. Current remediation efforts are mitigating impacts. 331302 400992777 false 2016-02-18T00:00:00-07:00 40.499410 -104.601990 FEE 0 0 0 true <_x0032_7_approved>false S false 0 0 Unknown 0 0 true false false true false 0 2016-02-19T09:40:47.547-07:00 401004170 401004170 FORM 19 SUBMITTED 401004170.pdf 401004170 401004260 ANALYTICAL RESULTS Williamson 43-12 Analytical Table and Laboratory Reports.pdf 1157627 401004170 401004261 SITE MAP Williamson 43-12 Figure 2.pdf 186426 401004170 401004262 TOPOGRAPHIC MAP Williamson 43-12 - Figure 1.pdf 986840 401004170 1 2016-03-14T00:00:00-06:00 0 0 true true false false false false 13 false On February 18, 2016, a historic release was discovered during facility plug and abandonment activities at the Williamson 43-12 location. Approximately 1,450 cubic yards of impacted material were removed and transported to the Waste Management Facility in Ault, Colorado for disposal under PDC waste manifests. 10 soil samples (SS01 – SS03 and SS05 – SS11) were collected from the sidewalls of the final excavation extent at approximately 11 feet below ground surface (bgs). Soil samples were submitted to Summit Scientific Laboratories in Golden, Colorado for analysis of benzene, toluene, ethylbenzene, total xylenes (BTEX), naphthalene, and total petroleum hydrocarbons (TPH) - gasoline range organics (GRO) by Environmental Protection Agency (EPA) Method 8260B, TPH - diesel range organics (DRO) by EPA Method 8015, pH, and electrical conductivity (EC). Analytical results indicated organic compound concentrations were below COGCC Table 910-1 standards in all 10 soil sample locations. EC concentrations were in exceedance of regulatory standards in three (3) soil sample locations (SS02, SS06, and SS10). However, additional soil removal was not conducted as samples were collected below the designed root zone. Groundwater was encountered in the excavation area at approximately 13 feet bgs. Between February 25 and March 8, 2016, approximately 550 barrels of groundwater were removed using a vacuum truck and transported to a licensed disposal facility. A subsequent groundwater sample (GW01) was collected from the excavation area and submitted for laboratory analysis of BTEX. Analytical results indicated benzene concentrations were in exceedance of COGCC Table 910-1 groundwater standards at a detection of 5.1 µg/l. The excavation extent and soil and groundwater sample locations are illustrated on Figure 2. Soil analytical results are summarized in Table 1 and groundwater analytical results are summarized in Table 2. The laboratory reports are included as Attachment A. Thedalund loam, 1 to 3 percent slopes 13 5 850 1470 485 1275 Based on the soil analytical data provided herein, remaining hydrocarbon impacts in soil were successfully removed during excavation activities. Given the marginal benzene concentration detected in groundwater sample GW01, PDC feels that dissolved phase hydrocarbon impacts do not pose a future risk at this site. Consequently, PDC is requesting a No Further Action (NFA) determination for this location. 0 0 0 0 0 0 0 0 false false 0 0 false false true false false false false false true false false true 80 50 Thread was being aborted.